Middle/Senior Frontend Developer (React + TypeScript)

Sigma Software; Warszawa; On-site; PLN 150,000 - 230,000; Full time

Job summary

Sigma Software in Warszawa is seeking a Middle/Senior Front-end Developer to join our team and help deliver high-quality web applications.

You will develop and maintain responsive apps using React and TypeScript, collaborate with designers and back-end developers, and use GraphQL and Material UI to build polished UI components. English proficiency required.

Qualifications

• At least 3 years of experience as Front-end Developer.
• Hands-on with JavaScript and TypeScript.
• Experience with React.
• Good knowledge of GraphQL.
• Experience with Material UI.
• Experience with GitHub and other version control systems.
• Upper-Intermediate level of English.

Responsibilities

• Develop and maintain responsive web apps using React and TypeScript.
• Collaborate with designers and back-end developers to deliver seamless UX.
• Work with GraphQL for data fetching and manipulation.
• Build modern UI components using Material UI or similar libraries.
• Participate in code reviews, sprint planning, and product discussions.
• Contribute to performance and code quality improvements.

Skills

JavaScript

TypeScript

React

English (Upper-Intermediate)

Tools

GraphQL

Material UI

Git/GitHub

Job description

Company Description

We are looking for a Middle/Senior Front-end Developer to join our team and help us develop the best solutions for our clients.

Working as a Front-end Developer on this project requires a mindset where we plan, build, and deliver together as a team. As a group, we take shared responsibility for delivery, including speed, efficiency, and quality. We also take full responsibility for the operational condition of what we deliver.

As an individual, you’re expected to take ownership, drive initiatives forward, suggest, and incorporate improvements across all areas.

Does this sound like you? Take your chance and grow with us.

CUSTOMER

Our client is one of Europe’s biggest GameTech companies and owns of one of the largest mobile gambling platforms, with millions of users. It is a big company that follows a startup approach. The technology stack is modern and up-to-date.

Job Description

• Develop and maintain responsive web applications using React and TypeScript
• Collaborate with designers and Back-end developers to deliver seamless user experiences
• Work with GraphQL for data fetching and manipulation
• Build modern and accessible UI components using Material UI or similar libraries
• Participate in code reviews, sprint planning, and product discussions
• Contribute to continuous improvements in performance and code quality

Qualifications

• At least 3 years of experience as a Front-end Developer
• Hands‑on experience with JavaScript and TypeScript
• Experience with React
• Good knowledge of GraphQL
• Experience with Material UI
• Experience with GitHub and/or other version control systems
• Upper-Intermediate level of English